Method of using quaternary ammonium peroxysulfates



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METHOD OF USING QUATERNARY AMMONIUM PEROXYSULFATBS Filed May a, 1964 T Oa) I X '2 ff A 2 o O 8 :1 a 2 0 II: ""IO LL! 0..

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l l l I I o m w v e m o BSVHHONI BONVLQB'HEIH INVENTORS LOUIS H. DIAMONDJOHN H. BLUMBERGS United States Patent 3,353,902 METHOD OF USINGQUATERNARY AlVHVlONIUM PERUXYSULFATES Louis H. Diamond, Yardley, Pa.,and John H. Blumbergs, Highland Park, N.J., assignors to FMCCorporation, New York, N.Y., a corporation of New York Filed May 8,1964, Ser. No. 365,874 3 Claims. (Cl. 8-110) ABSTRACT OF THE DISCLGSUREAn improved class of bleaching agents has been found which is effectivein giving a high degree of brightness without degrading fabrics duringbleaching. These compounds are quaternary ammonium peroxysulfates havingthe formula:

and diquaternary ammonium peroxydisulfates having the formula:

in which R R R and R may be saturated aliphatic, saturatedcycloaliphatic or aromatic groups having up to 18 carbon atoms which arenot oxidized by peroxysulfates and which are attached to the nitrogenatoms through a carbon atom.

In addition, certain of these compounds have also been found useful asfabric softeners, namely those quaternary ammonium compounds in which atleast one of the alkyl groups has from about 12 to about 18 carbonatoms.

The present invention relates to an improved class of bleaching agents,and more particularly, to quaternary ammonium peroxyrnonosulfates anddiquaternary ammonium peroxydisulfates (hereinafter termedperoxysulfates).

In the process of laundering textile garments in domestic washingmachines, it is common to employ a bleaching agent in addition to adetergent to maintain the original whiteness of the garments afterlaundering. The bleaching agents which are commonly in use include suchcompounds as sodium hypochlorite, chlorinated isocyanuric acids, andpotassium persulfate.

These bleaching agents have been found to have certain drawbacks. Forexample, sodium hypoohlorite and chlorinated isocyanuric acids tend tocause a measurable amount of fabric degradation during bleaching and arecapable of causing localized overbleaching by direct contact of thebleach with the fabric. Bleaching with potassium monope'rsulfate reducesfabric degradation, but the bleaching action is inferior to sodiumhypochlorite. Further, potassium monopersulfate does not have a goodshelf life and thus loses its bleaching effectiveness upon extendedstorage.

As a result, there is a need for an effective bleaching agent that ismore active than the milder bleaching agents in common use but whichdoes not cause any measurable degradation of the fabric during thebleaching operation.

It is an object of the present invention to provide an active, stable,bleaching agent which is effective in giving a high degree of brightnesswithout degrading the fabric during bleaching.

3,3533% Patented Nov. 21, 1967 and =diquaternary ammoniumperoxydisulfates having the formula Il i [Rr-lII-RdzSzOa are eiiectivebleaching agents for bleaching fabrics and have good storage stability.In the above formulations, R R R and R may be saturated aliphatic,saturate-d cycloaii-phatic or aromatic groups having up to about 18carbon atoms which are not oxidized by peroxysulfates and which areattached to the nitrogen atom through a carbon atom. The aliphaticgroups may be straight chained, branch chained, or attached to form aheterocyclic group.

We have further found that certain of these quaternary ammoniumcompounds are effective as fabric softeners as well as bleaching agentsand can be employed for softening textiles While bleaching. Thequaternary ammonium compounds useful for this purpose are those havingonly saturated alkyl chains on the quaternary ammonium residue and inwhich at least one of the alkyl groups has from about 12 to about 18carbon atoms in the chain.

In accordance with the present invention, the quaternary ammoniumperoxyrnonosulfates and the diquater nary ammonium peroxydisulfates areproduced by reaction of a quaternary ammonium salt (preferably one inwhich the anion of the salt is a halogen element) and an inorganicmonoor dipersulfate. Typical reactions proceed according to thefollowing equations:

where R R R and R are saturated aliphatic, saturated cycloali-phatic, oraromatic groups having up to about 18 carbon atoms which are notoxidized by peroxysulfates and which are attached to the nitrogen atomthrough "a carbon atom. An alternate method for preparingmonopersulfates is carried out by reacting quaternary ammoniumhydroxides with Caros acid solutions.

The particular quaternary ammonium salt precursor which is chosen willdepend upon the requirements of the final quaternary ammoniumpersulf-ate. For example, if the final product is to be used for bothsoftening and bleaching of textiles or in detergent applications, aquaternary ammonium -salt having all alkyl groups, at least one of whichis a fatty alkyl group, is prefered. Examples of these are dodecyltrimethyl ammonium chloride, di-hydrogenated tallow dirnethyl quaternaryammonium chloride, and others. If the final product is to be used onlyfor bleaching, lower molecular weight quaternary ammonium saltprecursors can also be used with good effect such as tetrarnethylammonium chloride or tetraethyl ammonium chloride.

Most inorganic persulfate reagents can be used in making up thequaternary ammonium persulfate's, but for economic reasons, the commonlyavailable persulfates, e.g. the ammonium, potassium and sodiummonopersulfates and dipersulfates, are preferred. For example, in

the preparation of quaternary ammonium monoperoxysulfates, potassiummonopersulfate (potassium caroate) has been found most suitable.

In the preparation of the quaternary ammonium peroxymonosulfates, lowreaction temperatures should be employed, preferably not above 20 C. Lowtemperatures are required because these compounds have such a highactivity that they will react at higher temperatures with the salt whichis produced in situ to liberate free chlorine, and to convert thepersulfate compound to a sulfate. Preferred reaction temperatures arefrom about zero to about 20 C.

In the production of the diquaternary ammonium peroxydisulfates,reaction temperatures of zero to 20 C. are preferred but either higheror lower reaction temperatures can be employed since the diquaternaryammonium peroxydisulfates do not react with any of the salts formed insitu. Lower temperatures are preferred but only to prevent the finalproduct from being soluble in the reaction medium. At low temperatures,i.e. to C., the final product will crystallize from the reaction mediumwith a minimum of the product remaining soluble in the mother liquor.The use of temperatures substantially below 0 C. should also be avoidedbecause, at these lower temperatures, some of the starting material maycrystallize out of solution without being reacted and therefore willcontaminate the final product.

The reaction media employed depends, to large extent, upon thesolubility of the final product in the reaction media. It is chosen sothat the final product is relatively insoluble in the reaction mediawhile the precursor feed reactants remain soluble therein. For example,in the preparation of higher molecular weight, quaternary ammoniumperoxymonosulfates and diquaternary ammonium peroxydisulfates, water ispreferred because the final product is relatively insoluble in anaqueous reaction media whereas the feed reactants and the byproduct saltare sufficiently soluble to dissolve them in the reaction media. In thecase of lower molecular weight quaternary ammonium peroxymonosulfatesand diquaternary ammonium peroXydisulfates, a selective organic solventmedia is preferred because the final product has a high solubility inwater and recovery of the final product from a water medium would beextremely difficult. Suitable organic reaction media include aqueousmethanol, dimethyl formamide, mixtures thereof, and isopropylalcohol-aqueous mixtures.

The peroxysulfates which are suitable as bleaching agents in the presentinvention are those which have groups attached to the nitrogen atom thatare not oxidizable by any peroxysulfate, including bothmonoperoxysulfates and diperoxysulfates. These groups, which areattached to the nitrogen atom through a carbon atom, may

be saturated aliphatic, saturated cycloaliphatic, or aromatic groups.The aliphatic and cycloaliphatic groups must be saturated in order to benon-reactive with a peroxysulfate. The aliphatic and cycloaliphaticgroups may be unsubstituted or may contain substituents that arenonoxidizable by peroxysulfates. Examples of aliphatic or cycloaliphaticsubstituents that are nonoxidizable include carboxyl, alkoxy, ester,amido and nitro groups. The aliphatic groups may also have phenylsubstituents which are nonoxidizable and which conform to therequirements of aromatic groups set forth below. Substituents which canbe oxidized on an aliphatic or cycloaliphatic group and which thereforeare unacceptable include amino, hydroxyl, cyano, keto, halogens (exceptfluorine) and aldehydes.

In the case of aromatic groups, e.g. phenyl groups at tached to thenitrogen atom, those may be unsubstituted or contain substituents suchas carboxyl, alkoxy, ester, amide, nitro and halogen groups. Thearomatic group may also have aliphatic substituents which arenonoxidizable and which conform to the requirements of aliphatic groupsgiven above. Substituents which can be oxidized on an aromatic group andwhich therefore are unacceptable include amino, hydroxyl, keto, andaldehydes.

Examples of suitable peroxysulfates include quaternary ammoniummonoperoxysulfates such as Z-ethyl lauryltrimethyl monoperoxysulfate,2-ethyllauryl stearyl dimethyl monoperoxysulfate, 12-benzylstearyltrimethyl monoperoxysulfate, 2-phenylpalmityl lauryl dimethylmonoperoxysulfate, 10-m-chlorophenylstearyl trimethyl monoperoxysulfate,2-nitrostearyl trimethyl monoperoxysulfate, Z-methoxystearyl lauryldimethyl monoperoxysulfate, IO-cyclohexylstearyl ethyl dimethylmonoperoxysulfate, Z-carboxypalmityl lauryl dimethyl monoperoxysulfate,2-acetoxystearyl propyl dimethyl monoperoxysulfate, di-2-nitrostearyldimethyl monoperoxysulfate,

phenyl stearyl dimethyl monoperoxysulfate, di-p-nitrophenyl dimethylmonoperoxysulfate, and p-carboxyphenyl diethyl methyl monoperoxysulfate.

The effectiveness of one of these peroxysulfates, dimethyldi-hydrogenated tallow ammonium monoperoxysulfate (DDTAM), as ableaching agent compared with a conventional bleaching agent, potassiummonopersulfate, is illustrated in the attached drawing.

In the drawing, the increase in brightness of tea stained samples(reflectance increase) is plotted against the active oxygen content ofthe bleaching solutions used. As is evident from the drawing, thepresent bleaching agent is more effective in increasing the reflectance,and therefore, in brightening the sample than is (KHSO potassiummonopersulfate. The exact procedure employed in determining theseresults is given in Example 8.

The present class of peroxysulfates may be used in laundering solutionsin amounts suificient to supply up to about 30 parts per million ofactive oxygen based on the weight of the bleaching solution. Largerquantities may be used, but for economic considerations, larger amountsare undesirable; moreover, the bleaching efiect is sufficient at thisconcentration to satisfy home laundering requirements. The precisequantities used depends upon the particular peroxysulfate chosen. Forexample, if a lower alkyl quaternary ammonium peroxysulfate is selectedwhich is intended primarily as a bleaching agent without any fabricsoftening effect, it is added in amounts sufficient to supply about 30parts per million of active oxygen. On the other hand, if a long chainedquaternary ammonium peroxysulfate is employed to obtain a fabricsoftening effect, it can be added in amounts of about 0.1 to 0.15% onthe weight of the fabric. When using low concentrations of thesecompounds to obtain fabric softening, the bleaching effect will not beas substantial as when higher concentrations of the quaternary ammoniumpersulfates are employed. However, even at low concentrations, thebleaching effect aids in maintaining the original whiteness of thefabric while giving a softening effect; this is important becausesubsequent yellowing of fabrics treated with chemical softeners oftenoccurs due to chemical changes in the softener per so.

In utilizing the present reagents, the quaternary ammoniumperoxymonosulfates are preferred because these reagents are morereactive and are stronger oxidizing agents than the diquaternaryammonium peroxydisulfates. In addition, the quaternary ammoniumperoxymonosulfates have more active oxygen per molecular weight than theperoxydisulfates, and therefore, can be used in smaller amounts toobtain the same bleaching effect as is obtained with larger quantitiesof diquaternary ammonium peroxydisulfates.

The following examples are given to illustrate the invention and are notto be deemed limiting thereof.

Example 1 A charge of 7.56 grams of tetramethyl ammonium chloridedissolved in 75 grams of methanol was poured into a 250 ml. beaker. Tothe solution was added, with stirring, 6.85 g. of ammonium persulfatedissolved in 25 g. of dimethyl formamide. The reaction mixture wascooled to Theory, percent Found, percent Carbon 28. 22 28. 26 Hydrogen-7. 11 7.21 Nitrogen. 8. 23 8.32 Sulfur 18. 84 18.06 Active Oxyge 4. 704. 73 Chlorine None N one The product was identified as tetramethylammonium diperoxysulfate.

Example 2 The same procedure used in Example 1 was repeated except that14.5 grams of tetraethyl ammonium bromide was used instead of thetetramcthyl ammonium chloride. A white crystalline product weighing 11grams was recovered from the Rinco Evaporator. It had an active oxygencontent of 3.49% by weight. The crude product was purified byrecrystallization from methanol and analyzed:

Theory, percent Found, percent Carbon 42. 45 42. 8 Hydrogen. 8. 91 8. 86N itrogen.. 6. 19 6.21 Sulfun. 14. 17 13. 64 Active Oxyge 3. 53 3. 5Bromine None None The purified product was found to be essentially puretetraethyl ammonium diperoxysulfate.

Example 3 An 11.5 g. sample of Arquad 12 was poured into a 250 ml.beaker and mixed with 2.16 g. of ammonium persulfate dissolved in about10 ml. of water. Arquad 12 is a 50% solution of dodecyl-trimethylammonium chloride in aqueous isopropyl alcohol. No solid formation wasobserved in the reaction mixture at ambient temperatures. The mixturewas then slowly added to a liter of cold water with vigorous agitationand white solids commenced to precipitate from the solution. Thereaction mixture was then cooled to about C. and the crystallizedproduct was filtered from the mother liquor, washed twice with coldwater, and dried on a Rinco Evaporator under reduced pressure. Theproduct was a white solid weighing grams and having an active oxygencontent of 2.49% by weight. The product was purified byrecrystallization from methylene chloride and analyzed:

Theory, percent Found, percent methyl ammonium chloride. The resultantproduct was a white solid weighing 5.6 g. and having an active oxygencontent of 2.07% by weight. The product was recrystallized frommethylene chloride and analyzed:

Theory, percent Found, percent Carbon 59. 96 59. (J1 Hydrogen 11. 12 11.l0 Nitrogen 3. 68 3. 66 Sulfur 8. 42 8. 03 Active Oxygen 2. 10 2. 07

The product was identified as palmityl-trimethyl ammoniumdiperoxysulfate.

Example 5 The procedure of Example 3 was repeated except that thereagents employed were 11.5 g. of Arquad 18 and 1.69 g. of ammoniumpersulfate. Arquad 18 is a 50% solution of stearyl-trimethyl ammoniumchloride. A white solid product weighing 5.3 g. and having an activeoxygen content of 1.93% by weight was obtained. It was identified asstearyl-trimethyl ammonium diperoxysulfate.

Example 6 The procedure of Example 3 was repeated except that thereagents employed were 5.75 g. of diisobutylphenoxyethyl dimethylbenzylammonium chloride (Hyamine 1622) and 1.21 g. of ammoniumpersulfite. A white solid product weighing 5.0 g. and having an activeoxygen content of 1.73% by weight was obtained. It was identified asdiisobutylphenoxyethyl dimethyl benzylammonium diperoxysulfate.

Example 7 A charge of 44 g. of Arquad 2HT was dissolved in a 150 m1. ofmethanol and poured into a 400 ml. beaker. Arquad 2HT is a proprietarycomposition containing by weight of dimethyl di-hydrogenated tallowammonium chloride. The fatty alkyl groups in this proprietarycomposition contain approximately 65% C 30% C and 5% of C alkyl chains.The Arquad 2HT solution was cooled to 5 C. A solution made up of 15 g.of potassium monopersulfate (potassium caroate) assaying 88% dissolvedin 150 ml. of distilled water was then added to the Arquad 2HT solution.The reaction mixture was stirred and further cooled to 0 C. A whitesolid product crystallized from the reaction mixture and was separatedby filtration from the mother liquor. The resulting solids were washedtwice with ml. of a cold (5 C.) methanol-water mixture and dried in aRinco Evaporator under reduced pressure. The resultant white solidproduct weighed 36 g. and had an active oxygen content of 2.20% byweight. A sample of the product was purified by recrystallization frommethylene chloride and analyzed:

Carbon 55. 52 55. 31 Hydrogen. 10. 56 10. 41 Nitrogen 4. 32 4. 3OSulfur. 9. 88 9. 40 Active Ox 2. 47 2. 49

The product was identified as dodecyl-trimethyl ammoniumdiperoxysulfate.

Example 4 The same procedure used in Example 3 was repeated except thatthe reactants employed were 11.5 g. of Arquad 16 in place of Arquad 12and 1.78 g. of ammonium persulfate. Arquad 16 is a 50% solution ofpalmityl-tri- The resultant product was identified as dimethyl di-hydrogenated tallow ammonium monoperoxysulfate.

Example 8 7 thereafter immersing the swatches in the tea and continuingthe boiling for an additional minutes. The stained swatches were thansqueezed to remove excess fluid, dried, rinsed in cold water and dried.

Three of the stained cotton swatches were added to each of a series ofstainless steel Terg-O-Tometer vessels (produced by the US. TestingCompany) containing 1000 ml. of a 0.2% standard detergent solution at atemperature of 120 F. Measured amounts of each of the bleaches were thenadded to separate vessels sufiicient to correspond to predeterminedactive oxygen contents. The pH of the solutions in the vessels wereadjusted to 9.5 using soda ash. Cut-up pieces of white terry clothtoweling were added to provide a typical household wash water/ clothratio of 20: 1. The Terg-O-Tometer was then operated at 72 cycles perminute for minutes at a temperature of 120 F. At the end of the washcycle, the swatches were removed, rinsed under cold tap water and driedin a Proctor-Schwartz skein dryer. The tests were run in triplicate andinclude detergent blanks. Reflectance readings of the swatches weretaken before and after the wash cycle with a Hunter Model D-40Refiectometer using the blue filter. Each swatch was read twice (warpand fill) on either side, with a backing of 5 similarly soiled swatches.Fluorescent effect was excluded in all readings. The resultantreflectance increase over blank samples at various active oxygenconcentrations is given in the drawing for both the DDTAM and thepotassium peroxymonosulfate.

Example 9 The softening efiect of dimethyl di-hydrogenated tallowammonium monoperoxysulfate (DDTAM), produced by the method set forth inExample 7, was tested by the method set forth in ASTM Dl17555T. Thistest measures the number of standard flex abrasion cycles a cloth canwithstand before being abraded. The test was carried out as follows:Cotton samples having thread counts of 80 x 80 and 136 x 64, and aDacron sample were placed in a domestic washing machine and run througha domestic washing machine with a standard detergent. In the final rinse4.72 grams of DDTAM (100% active material) were added to the 18 gallonsof wash water. The total solids load was 7.5 pounds of (dry) cloth. Thispermitted the solution to deposit on the cloth 0.137% softener solidsbased on the weight of the cloth. A duplicate blank was also run inwhich no softener was added to the cloth. The samples thus treated wereplaced on the flex abrasion tester and the number of abrasion cycles wasrecorded before the cloth was Softening of the cloth is indicated by theincrease in abrasion cycles required to abrade the cloth. Cloth whichhas been treated with a standard amount of a softener has increasedflexibility and is more difficult to abrade. The greater the softeneraction, the greater the increase in abrasion cycles required.

Example 10 The procedure used in Example 7 was repeated except that thereagents used were 11.8 g. of Arquad 16 and 4.5 g. of potassiummonopersulfate. Arquad 16 is a proprietary solution containing 50% byweight of palmityl-trimethyl ammonium chloride. The resultant solidproduct weighed 5.8 g. and had an active oxygen content of 3.05% byweight. It was identified as palmitylas stearyl-trimethyl ammoniummonoperoxysnlfate.

Example 11 The procedure of Example 7 was repeated except that thereagents employed were 13.9 g. of Arquad 18 and 4.5 g. of potassiummonopersulfate. The resultant white solid product weighed 5.8 g. and hadan active oxygen content of 3.01% by weight. The product was identifiedas stearyl-trimethyl ammonium monoperoxysulfate.

Example 12 The procedure of Example 7 was repeated except that thereagents employed were 23.5 g. of Aliquot 207 and 6.0 g. of potassiummonopersulfate. The resultant white solid product weighed 20 g. and hadan active oxygen content of 2.02% by weight. The product was identifiedas distearyl dimethyl ammonium monoperoxysulfate.

Pursuant to the requirements of the patent statutes, the principle ofthis invention has been explained and exemplified in a manner so that itcan be readily practiced by those skilled in the art, suchexemplification including what is considered to represent the bestembodiment of the invention. However, it should be clearly understoodthat, within the scope of the appended claims, the invention may bepracticed by those skilled in the art, and having the benefit of thisdisclosure otherwise than as specifically described and exemplifiedherein.

What is claimed is:

1. A method for bleaching fabrics which comprises contacting saidfabrics with an effective amount of a bleaching agent selected from thegroup consisting of in which R R R and R are selected from the classconsisting of saturated aliphatic, saturated cycloaliphatic, and phenylgroups having up to about 18 carbon atoms, said groups not beingoxidized by peroxysulfates and being attached to the nitrogen atomthrough a carbon atom.

2. A method for softening fabrics which comprises contacting said fabricwith an aqueous dispersion of a compound selected from the groupconsisting of in which R R R and R are alkyl groups having up to about18 carbon atoms, and in which at least one of said alkyl groups has fromabout 12 to 18 carbon atoms.

3. Method of claim 2 in which the softening agent is dimethyl(ii-hydrogenated tallow ammonium monoperoxysulfate.

References Cited UNITED STATES PATENTS 3,042,622 7/1962 Kirschenbauer2S299 LEON D. ROSDOL, Primary Examiner.

MAYER WEINBLATT, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,353,902 November 21, 1967 Louis H. Diamond et a1,

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 2, line 60, for "prefered" read preferred column 3, line 28, for"to" read to a line 68, for "those" read these column 4, line 4, for hy1lauryltrimethyl" read Z-ethyllauryl trimethyl column 8, line 4, before"solid" insert white same line 4,

for "5 .8 g read 5 g. line 6 strike out "as stearyl-r".

Signed and sealed this 24th day of June 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. JR.

Attesting Officer Commissioner of Patents

1. A METHOD FOR BLEACHING FABRICS WHICH COMPRISES CONTACTING SAIDFABRICS WITH AN EFFECTIVE AMOUNT OF A BLEACHING AGENT SELECTED FROM THEGROUP CONSISTING OF